Your Pregnancy Environment
How the air you breathe, the food you eat, and the water you drink affect your baby-to-be
What you've heard: Living in a smoggy city increases the chance of birth defects.
What the truth is: A study of babies born in the Los Angeles area suggested that mothers exposed to auto exhaust and industrial emissions during the second month of pregnancy have a greater risk of giving birth to a baby with a specific type of heart problem, called a ventricular septal defect. Exposure to ozone, another ingredient in smog, during the second month was linked to other types of heart and blood vessel deformities (conotruncal heart defects, pulmonary artery/valve defects, and aortic artery/valve defects).
Most experts say the study wasn't strong enough to prove a link to air pollution. For one thing, they took a mother's residence at delivery and assumed that's where she lived during her second month. The study also didn't control for smoking -- a known risk for birth defects -- or the air quality where she worked during the day.
Experts like Donald Mattison, M.D., of the National Institute of Child Health and Human Development in Bethesda, Maryland, say they are more concerned about the effects of indoor air on pregnancy. Secondhand smoke is known to affect the fetus, and mold, which grows on dark, damp surfaces, can release spores harmful to a newborn's developing lungs.
What you can do: Chances of harm are small, but if you live in a particularly smoggy area like Los Angeles, Denver, or Houston, you may want to stay indoors on smog alert days. But don't avoid doing what you need to do. If you're worried about air quality, it's more important to keep a clean house and stay away from smokers than to move away from a smoggy city. Mold thrives when the humidity is over 40 percent, so try to keep moisture levels down by running the air conditioner or using a dehumidifier if necessary. You'll also want to check for any leaky windows and be sure to regularly clean household surfaces with diluted bleach, an antifungal spray, or an ammonia-based cleaner.